Re: [PATCH v6] arm pl011 serial: support multi-irq request
From: Greg KH <gregkh@linuxfoundation.org>
Date: 2021-08-13 07:19:24
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On Fri, Aug 13, 2021 at 11:31:30AM +0800, Bing Fan wrote:
quoted hunk ↗ jump to hunk
From: Bing Fan <redacted> In order to make pl011 work better, multiple interrupts are required, such as TXIM, RXIM, RTIM, error interrupt(FE/PE/BE/OE); at the same time, pl011 to GIC does not merge the interrupt lines(each serial-interrupt corresponding to different GIC hardware interrupt), so need to enable and request multiple gic interrupt numbers in the driver. Signed-off-by: Bing Fan <redacted> --- drivers/tty/serial/amba-pl011.c | 39 +++++++++++++++++++++++++++++++-- 1 file changed, 37 insertions(+), 2 deletions(-)diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index e14f3378b8a0..eaac3431459c 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c@@ -1701,6 +1701,41 @@ static void pl011_write_lcr_h(struct uart_amba_port *uap, unsigned int lcr_h) } } +static void pl011_release_multi_irqs(struct uart_amba_port *uap, unsigned int max_cnt) +{ + struct amba_device *amba_dev = container_of(uap->port.dev, struct amba_device, dev); + int i; + + for (i = 0; i < max_cnt; i++) + if (amba_dev->irq[i]) + free_irq(amba_dev->irq[i], uap); +} + +static int pl011_allocate_multi_irqs(struct uart_amba_port *uap) +{ + int ret = 0; + int i; + unsigned int virq; + struct amba_device *amba_dev = container_of(uap->port.dev, struct amba_device, dev); + + pl011_write(uap->im, uap, REG_IMSC); + + for (i = 0; i < AMBA_NR_IRQS; i++) { + virq = amba_dev->irq[i]; + if (virq == 0) + break; + + ret = request_irq(virq, pl011_int, IRQF_SHARED, dev_name(&amba_dev->dev), uap); + if (ret) { + dev_err(uap->port.dev, "request %u interrupt failed\n", virq); + pl011_release_multi_irqs(uap, i - 1); + break; + } + } + + return ret; +}
This function looks identical to pl011_allocate_irq(), so what is the difference here? Why is this still needed at all? What does it do that is different from pl011_allocate_irq()? confused, greg k-h